package com.iiot.util;

/** 根据经纬度求两个点之间的距离，单位是米 */
public class DistanceUtil {

    private static final double EARTH_RADIUS = 6378.137; // 地球半径，单位km

    private static double rad(double d) {
        return d * Math.PI / 180.0;
    }

    public static double GetDistance(double lat1, double lng1, double lat2, double lng2) {
        double radLat1 = rad(lat1);
        double radLat2 = rad(lat2);
        double a = radLat1 - radLat2;
        double b = rad(lng1) - rad(lng2);
        double s =
                2
                        * Math.asin(
                                Math.sqrt(
                                        Math.pow(Math.sin(a / 2), 2)
                                                + Math.cos(radLat1)
                                                        * Math.cos(radLat2)
                                                        * Math.pow(Math.sin(b / 2), 2)));
        s = s * EARTH_RADIUS * 1000;
        s = Math.round(s * 10000) / 10000;
        return s;
    }

    public static void main(String[] args) {

        double lat1 = 22.31004;
        double lng1 = 114.02560;
        double lat2 = 22.32004;
        double lng2 = 114.01560;

        double getDistance = GetDistance(lat1, lng1, lat2, lng2);

        System.out.println(getDistance);
    }
}
